2017 James B. Macelwane Medal Winner
Robert E. Kopp, Michael P. Lamb, Yan Lavallée, Wen Li, and Tiffany A. Shaw were awarded the 2017 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 13 December 2017 in New Orleans, La. The medal is for “significant contributions to the geophysical sciences by an outstanding early career scientist.”
Citation
Professor Yan Lavallée is recognized for his innovative high-temperature experimentation in the solid Earth sciences. His laboratory is devoted to experiments performed at the extreme conditions relevant in volcanic systems. The experiments are designed to advance understanding of volcanic, geothermal, and other dynamic geological processes. His research program leads the world in elucidating linkages between magma properties and rheology and the behavior (explosive versus effusive) of volcanic systems.
Lavallée obtained his B.Sc. honors degree from McGill University in Canada, and his early research involved analogue modeling of caldera subsidence. He continued his research on calderas with a study of a Peruvian volcano to earn his M.Sc. in space studies at the University of North Dakota in the United States. His passion for high-temperature experimentation, however, derives from his Ph.D. studies at Ludwig Maximilian University in Munich, Germany.
His Ph.D. studies focused on lava dome–producing volcanoes; these eruptions are unpredictable and can rapidly switch from quiescent effusive behavior to catastrophic explosive activity. Understanding the switching mechanisms has been a topical line of research for 20+ years. Lavallée has provided a quantitative understanding of how the porosity, permeability, and crystallinity of dome magmas affect rheology and, together with effusion rates, dictate volcanic consequences. His experimental data on crystal-rich dome lavas demonstrated the non-Newtonian strain rate dependence of magma viscosity and showed the commonly employed Einstein–Roscoe equation to be totally inappropriate for crystal-rich magmas. This result launched an industry of studies into the effects of crystals and bubbles on magma rheology. His work also made connections between field observations on lava domes, experimental deformation of natural dome magmas, and geophysical signals expressed in nature and captured in the lab. His insightful analysis of these data sets produced a means of forecasting lava dome collapse events based on seismic signals.
Lavallée is now a professor of volcanology in the Department of Earth, Ocean and Ecological Sciences, where he has established a vibrant, well-equipped (approximately US$2.5 million) laboratory for experimentation on volcanic materials. Recent high-impact studies have explored the interplay of frictional heating and vesiculation, suggesting that thermal heating may play a larger role in explosive eruptions than previously recognized. His experiments also explored the capacity of “tuffisite networks” (veins of pyroclastic particles) within lava domes to control permeability and thus explosivity. His experiments showed how the timescale of “healing” of the tuffisite veins provides a means of transitioning to, and cycling between, effusive to explosive eruption by gas repressurization. Lavallée has made, and will continue to make, high-impact, important contributions to our understanding of volcanic processes through thoughtful experimentation.
Response
It is with great gratitude that I receive the James B. Macelwane Medal; I extend my thanks to Kelly and my nominators, who certainly expressed generous words in favor of my contributions to geophysical sciences! I am most delighted to accept this prestigious honor and humbly stand alongside the illustrious scholars who have received it before me.
I was 5 years of age when, one summer afternoon in the province of Quebec, I asked my mother, “Maman, qu’est ce qu’on est?” Gobsmacked, she knew very well that the question I (and I imagine many of you) was troubled with could not be answered, at least, not simply. She looked at me, shrugged her shoulders, and replied that she didn’t know. That initiated my search for answers—answers I sought in geosciences. It’s been nearly 20 years since I began to study the Earth, and I count myself lucky to have faced very few problems that have cast a shadow large enough to darken a week at work. We’re privileged in that we get to see the world through our work, and we all agree, it’s a wonderful place, well worth knowing.
In my career to date, I have had the rewarding opportunity to work with well over 100 collaborators—in laboratories, at observatories, in factories, and everyone I met in the field—so I may not be able to thank all of you here, but please see these words as a kind reminder of the superb times we have spent together and of the findings we have achieved together. You have contributed in a million ways, and I share this honor with you.
My undergraduate years at McGill University taught me that everything can be achieved with dedication, hard work, and, of course, fun! Thanks to John Stix, Ben Kennedy, Alain Garand, and Don Francis for teaching me that important bit of wisdom, mixed with a great deal of geology! During my master’s degree in space studies at the University of North Dakota, I was lucky enough to work alongside great mentors, Shanaka de Silva, Bob Andres, Mike Gaffey, Stephen Johnson, and Jeff Byrnes, who taught me as much about being a versatile and balanced scientist as about volcanoes, space, and history.
During my doctoral studies at the Ludwig Maximilian University in Munich, Germany, the field of geosciences exploded before my eyes. The technological revolution we are now witnessing has opened up countless possibilities, and I feel fortunate to have met a body of scientists to undertake work on the new challenges of modern volcanology. First, thanks to Don Dingwell for providing the best supervision and mentoring I needed: I owe the vast majority of my knowledge about life as an academic to you, a true friend and a great inspiration! Thanks also to the many I met in my time in Munich: Ulli Kueppers, Kai-Uwe Hess, Betty Scheu, Basti Müller, Jon Castro, Hugh Tuffen, Alex Nichols, Oliver Spieler, Jeremie Vasseur, Fabian Wadsworth, and many more.
In 2012, I moved to the University of Liverpool and established the Experimental Volcanology and Geothermal Research Laboratory to discover that even “Eight Days a Week” (as put forth by the Beatles) were not enough to maximize the scientific opportunities that were yet again growing in number. I thank Felix von Aulock, Silvio de Angelis, and more colleagues in the Faculty of Science and Engineering than I can begin to mention.
I would also like to take the opportunity to thank all those who push larger-than-life initiatives in geosciences, in particular, the Krafla Magma Testbed; I’m proud to be among such company as we aim to establish the first magma observatory. It is a reminder that “the wall between reality and fantasy is sometimes so small and not so tall” when we collectively join efforts for the advancement of our field (as pondered by Raphael Gualazzi in “Reality and Fantasy”).
Finally, a very sincere thanks to my partner, Jackie Kendrick, whom I’m fortunate enough to work alongside. And thanks to all of my friends and family, scattered around this beautiful Earth.
In closing, many thanks to the AGU community for this heart-warming honor. In return, I promise to keep you entertained by publishing science as provocative as it is insightful and inspirational for many years to come.